From ae30d40e626fb35fc83769f4caf1c95d48e58396 Mon Sep 17 00:00:00 2001
From: Alessandro <misterroot@gmail.com>
Date: Thu, 24 Oct 2024 22:25:14 +0200
Subject: [PATCH] poc: more responsive carousel pagination dots (#2220)

* chore(carousel): more responsive dots

* chore: minor change

* chore: update

* chore: update

* chore: minor change
---
 src/components/carousel/carousel.component.ts | 48 ++++++++++++-------
 1 file changed, 31 insertions(+), 17 deletions(-)

diff --git a/src/components/carousel/carousel.component.ts b/src/components/carousel/carousel.component.ts
index dcae6044..6237888c 100644
--- a/src/components/carousel/carousel.component.ts
+++ b/src/components/carousel/carousel.component.ts
@@ -94,6 +94,7 @@ export default class SlCarousel extends ShoelaceElement {
   private autoplayController = new AutoplayController(this, () => this.next());
   private readonly localize = new LocalizeController(this);
   private mutationObserver: MutationObserver;
+  private pendingSlideChange = false;
 
   connectedCallback(): void {
     super.connectedCallback();
@@ -261,6 +262,9 @@ export default class SlCarousel extends ShoelaceElement {
   @eventOptions({ passive: true })
   private handleScroll() {
     this.scrolling = true;
+    if (!this.pendingSlideChange) {
+      this.synchronizeSlides();
+    }
   }
 
   /** @internal Synchronizes the slides with the IntersectionObserver API. */
@@ -277,20 +281,28 @@ export default class SlCarousel extends ShoelaceElement {
         }
 
         const firstIntersecting = entries.find(entry => entry.isIntersecting);
+        if (!firstIntersecting) {
+          return;
+        }
 
-        if (firstIntersecting) {
+        const slidesWithClones = this.getSlides({ excludeClones: false });
+        const slidesCount = this.getSlides().length;
+
+        // Update the current index based on the first visible slide
+        const slideIndex = slidesWithClones.indexOf(firstIntersecting.target as SlCarouselItem);
+        // Normalize the index to ignore clones
+        const normalizedIndex = this.loop ? slideIndex - this.slidesPerPage : slideIndex;
+
+        // Set the index to the closest "snappable" slide
+        this.activeSlide =
+          (Math.ceil(normalizedIndex / this.slidesPerMove) * this.slidesPerMove + slidesCount) % slidesCount;
+
+        if (!this.scrolling) {
           if (this.loop && firstIntersecting.target.hasAttribute('data-clone')) {
             const clonePosition = Number(firstIntersecting.target.getAttribute('data-clone'));
 
             // Scrolls to the original slide without animating, so the user won't notice that the position has changed
             this.goToSlide(clonePosition, 'instant');
-          } else {
-            const slides = this.getSlides();
-
-            // Update the current index based on the first visible slide
-            const slideIndex = slides.indexOf(firstIntersecting.target as SlCarouselItem);
-            // Set the index to the first "snappable" slide
-            this.activeSlide = Math.ceil(slideIndex / this.slidesPerMove) * this.slidesPerMove;
           }
         }
       },
@@ -307,10 +319,9 @@ export default class SlCarousel extends ShoelaceElement {
 
   private handleScrollEnd() {
     if (!this.scrolling || this.dragging) return;
-
-    this.synchronizeSlides();
-
     this.scrolling = false;
+    this.pendingSlideChange = false;
+    this.synchronizeSlides();
   }
 
   private isCarouselItem(node: Node): node is SlCarouselItem {
@@ -380,7 +391,7 @@ export default class SlCarousel extends ShoelaceElement {
   }
 
   @watch('activeSlide')
-  handelSlideChange() {
+  handleSlideChange() {
     const slides = this.getSlides();
     slides.forEach((slide, i) => {
       slide.classList.toggle('--is-active', i === this.activeSlide);
@@ -485,11 +496,14 @@ export default class SlCarousel extends ShoelaceElement {
     const nextLeft = nextSlideRect.left - scrollContainerRect.left;
     const nextTop = nextSlideRect.top - scrollContainerRect.top;
 
-    scrollContainer.scrollTo({
-      left: nextLeft + scrollContainer.scrollLeft,
-      top: nextTop + scrollContainer.scrollTop,
-      behavior
-    });
+    if (nextLeft || nextTop) {
+      this.pendingSlideChange = true;
+      scrollContainer.scrollTo({
+        left: nextLeft + scrollContainer.scrollLeft,
+        top: nextTop + scrollContainer.scrollTop,
+        behavior
+      });
+    }
   }
 
   render() {